Have you ever woken-up in the morning without the ability to do anything but stare straight ahead into space? You sit up on the side of the bed and just stare off into space unable to rouse yourself into preparations for the day? You feel hypnotized as in a trance state. You know what is going on round you but you just need to stare straight ahead for a few seconds before you can get moving. This is an example of the impact of a brain state transition on your behavior and thinking patterns. These sorts of brain state transitions are called parasomnias and are essentially trance-like states. They can result in the most bizarre and interesting behavioral phenomena, including unusual dreams.
There are a range of such states and they can teach us about dreams. Most of us have heard about or witnessed sleepwalkers. These are people who walk in their sleep. Their eyes may be wide open but they are nevertheless asleep and dreaming. Their dreams usually involve unpleasant events and natural disasters. They may be trying to flee a monster or find a lost loved one and so on. In sleep terrors a child will sit up on the side of bed with eyes wide open and scream bloody terror. They are typically experiencing a nightmare, a supernatural horror is about to annihilate them. Often after awakening the child may know that he was dreaming but be amnestic for the content of the dream. You may have also heard about, or experienced yourself, the condition of sleep state paralysis. The paralysis refers to the fact that you are half-awake but cannot move your limbs. The dream state that accompanies sleep paralysis often consists of bizarre images and sometimes frightening nightmares of a supernatural being sitting atop the chest and restricting your breathing. In other parasomniac states you may be dreaming but aware that you are dreaming-yet you cannot wake up. People find that if they can move a little finger or a toe they can wake themselves up from this frightening state. Yet another variation is the lucid dream. Here the person typically wants to stay asleep but is near waking. He knows that he is dreaming and wants to experiment with the dream world and so does not want to wake up. Very often however the content of the lucid dream proceeds beyond the dreamer’s control and some event in the dream will cause an abrupt awakening. Other evidence suggests that the dreams that occur in these transitional states are strongly correlated with creativity. It is these dreams that produce those famous examples of scientific breakthroughs or artistic innovations....There are many, many other examples of these “parasomnias” or half-way states between sleep and wakefulness, but what might they tell us about sleep and dreams?
In a recent review of the brain regulatory systems that control brain state transitions (Sleep state switching. Saper CB, Fuller PM, Pedersen NP, Lu J, Scammell TE. Neuron. 2010 Dec 22;68(6):1023-42. Review. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3026325/), Saper and colleagues noted that these state control systems are typically composed of neural networks that act to mutually inhibit one another’s activity. As one circuit or network rises in activity levels the other network is inhibited and vice versa. For example, as REM-on cells in the pons become active they automatically inhibit REM-off neurons in the Pons until the rate of change in firing of the two populations is maximal near the inflection point (the half-way point in the transition). At that point you rapidly see the behavioral state change. It is as if two huge populations of neurons, some of which want to stay in state 1 are battling a second population of neurons who want to eliminate neurons in state 1. The battle rages between the two sets of neurons and while the battle rages we are in a trancelike, twilight, transitional state. But once one side gains an edge in the battle, the other side rapidly starts to turn tail and run causing a sudden turnover in state.
It is the battle, rather than the victory that gives rise to interesting dreams.